Rabbit's cousin (4)
I believe the answer is:
hare
'rabbit's cousin' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for hare that I've seen before include "Sort of rabbit" , "animal running in fields" , "Rabbit-like animal" , "Mammal like a large rabbit" , "Game, -- and hounds" .)